This is what the police said in its preliminary report submitted to Udhampur District Magistrate Shahid Iqbal Choudhary.

"During the course of preliminary investigation, it transpired that the terrorists involved in the attack are trained 'fidayeens' and backed by Pakistan's ISI in order to wage war against the government of India," it said.

Giving details of the attack in which two BSF personnel and one terrorist were killed, the police said an FIR has been registered under various sections of Ranbir Penal Code, Arms Act and Unlawful Activities Prevention Act.

One of the two Pakistani terrorists was caught alive and he is being interrogated.

Meanwhile, BSF Inspector General (Jammu Frontier) Rakesh Sharma said a probe is underway to ascertain the route that the terrorists had taken while crossing over into India.

"It is a matter of investigation. Interrogation is being done by J&K Police. I cannot definitely say anything on that," he said when asked about the route used by the terrorists to infiltrate from Pakistan.

At the same time, he said there is best possible security along International Border and it is not easy to cross over to this side.

Asked whether BSF was a target, he said it was chance as the force was not the main target of terrorists. "They were looking for a target and BSF convoy passed and it was targeted."

On whether the attack was meant for Amarnath yatra convoy, he said, "It is matter of interrogation what was their intentions. One terrorist has been captured alive and I hope to get some facts out".

He said that BSF will conduct assessment of border belt along IB and "if there is any goof-up in security we will take action".